Improvement in rock-drills



UNITED STATES PATENT CEEICE.

DAVID RALSTON, OF CARLISLE, PENSYLVANIA.

IMPROVEMENT IN ROCK-DRILLS.

Specification forming part of Letters Patent No. 29,716, dated August 21, 1860.

To all whom it may concern.-

Be it known that I, DAVID RALsToN, of Carlisle, in the county of Cumberland and State of Pennsylvania, have invented certain new and useful Improvements in Rock-Drills; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing, and to the letters of reference marked thereon.

In the annexed drawing making a part of this specification, A represents a carriage, which consists of two bars connected together at a proper distance apart, being provided with handles at one end and with wheels at the other, as shown, in such a manner that a man may wheel it about to any desired place.

B represents a frame, which is secured upon the carriage A, being hinged to it, as represented at :12. The rear portion of the frame is connected to the carriage by means of a standard e in such a manner that it may be adjusted to or from the said carriage at the will of the operator, I.thus changing the inclinationof the said frame, and consequently of the drill, which is secured to it.

The frame B consists of two vertical bars G G and two horizontal bars H, which are framed Vtogether in a substantial manner. Between the two vertical bars the drill D is secured, passing through guides I I near the top and bottom of said bars.

C represents a strong spring, which is secured between the two bars H, running parallel with them. This spring has its fulcrum at the set-screw J, and is provided with an opening near its vibrating end, through which the drill D passes.

Erepresentsacross-head, which is provided with an opening in which a female screw is cut, which corresponds with a male screw upon the drill, said drill being made to pass through this in the cross-head. The crosshead is attached to the under side of the spring by means of two staples or loops m, which pass around projections on the said cross-head, these projections being grooved, so that the guides l? F on the bars G G will tit in said grooves and keep the cross-head in proper position. It will be seen that by this arrangement when the spring is moved up and down the drill will also move with it, the two being connected together.

Upon the top of the frame B is secured a ratchet-wheel d in the position seen.

a represents a connecting-rod, one end of which attaches to the spring G and the other to one end of a bell-crank b. To the other end of the bell-crank is attached a ratchet which plays in the teeth of the ratchet-wheel d. The spring C imparts motion to the ratchet through the connecting-rod a and the crank l), and thus a rotary motion is given to the ratchet-wheel 0l. The drill passes through the center of this ratchetwheel,and being provided with a longitudinal groove, in which plays a lug or pin in the eye of the wheel, the said drill has a rotary motion imparted to it by the wheel, while it is allowed to play through it freely vertically. A shaft LL lies across the front portion of the bars H, said shaft being provided with a crank-handle M and two arms pp. As the shaft L 1is made to revolve, the arms p 1o catch under the end of the spring C and cause it to rise and fall.

By the arrangement ofthe several parts first described an up-and-down motion and at the same time a rotary motion with a progressive motion are communicated to the drill. The spring and its attachments give an upand down motion, the ratchet-wheel and its attachments'give a rotary motion, and the screw in the cross-head, together with the screw upon the drill, give fiit a progressive motion downward into the rock when drilling.

The strength ot' the-spring, and consequente ly of the stroke of the drill, may be regulated by means of the set-screw- J.

'The slotted standard e allows the inclination of the drill to bechanged and varied to suit. circumstances.

Having thus fully described my invention, what I claim as new,and desire to secure by Letters Patent, is-

The arrangement of the adjustable frame B, the spring` C, the drill D, the cross-head E, and guides F, with the connecting-rod a, the bell-crank I1, the ratchet c, and the ratchetwheel d, the several parts being constructed and connected substantially as and for the purpose specified.

l) AVID RALSTON.

Witnesses:

A. L. SPoNsLER, S. ELLIOTT. 

